Screen



s. B. DAVIES- Aug. 30, 1938.

' SCREEN Filed Dec. 17. 1956 Patented Aug. 30, 1938 UNITED STATES SCREEN Stanley B. Davies, Kingston, Pa., vassignor to Royer Foundry & Machine Company, Kingston, Pa., a corporation of Pennsylvania Application December 17, 1936, Serial No. 116,429 X 7 Claims.

This invention relates to screening apparatus, and more particularly to improvements in screen grids.

The primary object of the present invention is to provide a screen grid including fins and which grid may be readily assembled or disassembled; in which broken or damaged parts may be readily removed and replaced; and which will not clog or choke up with the material being screened.

The advantages of the present invention are effected by providing grid bars of a screen with removable fins disposed transversely of the grid bars in apertures of suitable size formed in the grid bars and removably held therein by keys.

To prevent clogging, the fins are tapered, their broader edges constituting, with the top edges of the grid bars, the top surface of the screen grid, the tapering sides of the fins diverging toward the bottom so that any materials which will pass the spaces between the wide upper ends of the fins will inevitably go on down through the gradually increasing spaces between the tapered fins.

In some instances, it has been found advantageous to provide inwardly directed tongues on the lower portion of the walls of the hopper'of the screening apparatus which are opposite and cooperate with the edges of the fins carried by the grid bars next adjacent to the walls to prevent material from escaping freely down between the Walls of the hopper and the adjacent grid bars without being subjected to the screening action of the screen grid. The edges of the adjacent tongues and fins, however, diverge downwardly so as to provide gradually increasing openings as is provided in the body of the screen between the adjacent fins.

Figure 1 shows a fragmentary elevational view of the screen grid as applied to the screening apparatus of the Royer Patent 2,020,800;

Figure -2 is a plan view of a portion-of the screen grid;

Figure 3 :is a vertical transverse sectional view;

Figure 4 is a perspective view of a wedgeshaped fin;

Figures 5,-6, 7 and 8 showvariousstages-inthe assembly of the-grid bars and fins;

Figure 9 is a modification showing a fin with out the bottom kerf; and

Figure 10-is a transverse section on the line -I-| 0 of Figure2.

- In the drawing, my invention is shown applied to the screening apparatus of the .Royer Patent No. 2,020,800, but it is contemplated that itmay be used in any other types of screening apparatus.

The grid "bars l are provided with removable transverse wedge-shaped fins 3. each grid bar I has a series of elongate spaced apertures 4 along its length, substantially below its top edge. The elongate'apertures 4 include top and bottom walls and 6 parallel respectively to the top edge of the grid bar and downwardly converging side walls '1 and 8, one of the side walls having an inwardly directed ledge 9, the upper edge of the ledge extending from the side wall 1 into the aperture and the face of the ledge being parallel to the opposite side 8 of the aperture and extending downwardly to meet the bottom wall 5 of the aperture. It will be observed that the space between the upper edge of the ledge 9 and the top'wall of the aperture 5 forms an ofiset portion to of the aperture.

The wedge-shaped fins 3 are removably secured in the respective apertures 4 transversely of the grid bars I, the ends ll of the respective fins projecting from each side of the grid bars I and spaced substantially from the alternate grid bars 2 of the screen.

Each wedge-shaped :fin 3 is provided with kerfs l2 and I3 in its top and bottom edges of substantially the same width as the thickness of the stock from which the supporting grid bars are made. The depth .of the upperkerf is determined by the amount of stock between the top edge of the grid bar and the top wall 5 0f the aperture while thedepth of the bottom kerf I3 .is determined .only by thedepth of the fin 3 which in turn must not be greater in depth than the depth of the elongate aperture 4 from top to bottom. In some instances, the fins 3 maybe of less depth than .the aperture so that the bottom kerf I3 is absent, and in such a case the bottom of the fin seats upon the bottom 9 of the offset [0 of the aperture as shown in Figure .9. 5

In order to removably secure the fins 3 in positions, keys M of generally rectangular shape are disposed in the body l5 of the aperture not occupied by the wedge-shaped fins, the outer side 16 of the key abutting one wall of the aperture, the inner side ll of the keyabutting the fin for a portion of its'length and the-top and bottom edgesabutting respectively the top and bottom walls of the aperture. The keys maybe secured in place by a driven fit or by swaging,

To this end, :5

brazing, spot welding or any other convenient manner.

The grid provided with the transverse fins 3 is readily assembled by placing each of the wedge-shaped fins transversely in the body P5 of an aperture as illustrated in Figure 6, then moving it vertically upwardly so that the upper kerf l2 straddles the portion of the grid bar between the top edge of the grid bar and the top of the elongate aperture as in Figure 7 and finally moving the fin laterally so that it takes up its position in the offset portion ill of the aperture,

the lower kerf l3 straddling and seating upon' the ledge as shown in Figure 8. The key may then be disposed in the body 15 of the aperture and secured in place in any appropriate manner.

It has been found advantageous to provide parallel vertically disposed inwardly directed tongues i8 on the lower portion of the inner walls 59 of the hopper opposite and cooperating with the edges of the fins carried by the grid bar next adjacent the wall. Each tongue H3 is shaped so that its edge slopes inwardly and downwardly from the wall of the hopper toward the top surface of the respective. fin adjacent thereto, such edge-continuing vertically for a portion of its length adjacent'but spaced from the edge of the fin and then diverging from the edge of the fin to the Wall of the hopper. The ends of the fins 3 in the grid bar next adjacent the tongues are spaced substantially therefrom and their outer edges 20 slope downwardly away from the tongues from top to bottom so that there is a gradual increasing opening between the tongues it and fins 3 adjacent thereto. The tongues it are fixed to the walls I 9 of the hopper in any convenient fashion. 7

The grid bars, fins, and tongues carried by the walls of the hopper, or a stationary frame constitute a generally planar upper screen grid surface characterized by the fact that material which passes through the openings in that surface must inevitably go on down through the gradually increasing spaces between the tapered fins and tongues.

Such changes and adaptations from the particular construction herein disclosed, as are within the skill of the mechanic, may be made with- But departing from the substance of this inven- I claim:

1. A grid bar having a series of longitudinally spaced apertures, each aperture being spaced below the top edge of the grid bar, the side walls of each aperture converging downwardly, one of the side walls having an outstanding ledge, and wedge-shaped fins seated transversely of the grid bar in the respective apertures, the wedge-shaped fins being provided with kerfs in their top edges, the kerf of the fin straddling the portion of the grid bar above the top of the respective apertures and thebottom of the fin being seated on the ledge of the aperture, and a key disposed in the aperture to hold the fin in place.

2. A grid bar having a series of longitudinally spaced elongate apertures, each aperture being spaced below the top edge of the d Said; aperture comprising a substantially rectangular body portion and an offset at the upper portion thereof and wedge-shaped fins seated transversely of the grid bar in the ofiset portion of the apertures, the wedge-sh aped fins being provided with kerfs in their top edges, the kerf of the fin straddlll'lg the portion of the grid bar above the top of the respective ap erturcs. and he bottom of the fin being seated on the bottom of the offset portion of the aperture, and a key disposed in the substantially rectangular body portion of the aperture to hold the fin in place.-

3. A grid bar having a series of longitudinally spaced apertures, each aperture being spaced be low the top edge of the grid bar, and having top and bottom walls parallel with the top edge of the grid bar, the side walls of the aperture com.

verging downwardly, one of the side walls having L an outstanding ledge including an upper edge parallel with the top edge of the grid bar and a face parallel with the opposite side of the aperture and wedge-shaped fins seated transversely of the grid bar in the respective apertures, the

wedge-shaped fins being provided with kerfs in their top and bottom edges, the upper kerf of each fin straddling the portion of the grid bar above the top of the respective apertures and the bottom ker'f of the fin straddling and seating on the ledge of the aperture, and a key disposed in the aperture to hold the fin in place.

4. A grid bar having a series of longitudinally spaced elongate apertures, each aperture being spaced belowthe top edge of the grid bar, said aperture comprising a substantially rectangular body-portion and an offset at the upper portion thereof and wedge-shaped fins seated transversely of the grid bar in the offset portion of the apertures with the upper edges substantially flush i 5. A grid bar having a series of longitudinally spaced apertures, each aperture being spaced below the top edge of the grid bar, and having top and bottom walls parallel respectively to the top edge of the grid bar, the side walls of the aperture converging downwardly, one of the side walls having an outstanding ledge, the upper edge of the ledge extending outwardly into the aperture and the face of said ledge being parallel to the opposite wall of the aperture and extending downwardly to meet the bottom wall of the aperture, and wedge-shaped fins seated trans versely of the grid bar in the respective apertures with their upper edges substantially flush with the top of the grid bars, the wedge-shaped fins being provided with kerfs in their top and bottom edges, the upper ker-f of the fin straddling the portion of the grid bar above the top of the respective apertures and the bottom kerf of the fin straddling and seating on the ledge of the aperture, and a key disposed in the aperture to hold the fin in place.

6. In combination, a screen structure including a stationary frame and a plurality of grid bars movable with respect to said frame, and extending parallel with the two opposite side walls thereof, the grid bars adjacent said two opposite walls of the frame being provided with transverse fins having ends projecting toward said walls, said ends being downwardly inclined from said walls, tongues on the walls of the frame substantially opposite and projecting toward the respective fins, the edges of the tongues extending above the median position of the tops of the fins and sloping downwardly toward such posi- .tion, then continuing vertically downwardly for a portion of their length and then diverging from the ends of the fins to the walls of the hopper at a point below the median position of the bottom of said fins, said tongues being sufficiently long to be opposite a portion of said fins at all positions of the latter during their movement.

7. In combination, a screen structure including a stationary frame and a plurality of grid bars movable with respect to said frame, and extending parallel with the two opposite side walls thereof, the grid bars adjacent said two opposite walls of the frame being provided with transat all positions of the latter during their move- 10 ment.

STANLEY B. DAVIES. 

